Tus qauv ntawm lub database

Cov ntaub ntawv, raug lub hauv paus ntawm lub ntau yam hluav taws xob cov ntaub ntawv interchange systems yog ib lub koom haum nyob rau hauv ib tug tshwj xeeb txoj kev thiab yog hu ua database. Yuav kom to taub cov tswvyim no, raws li zoo raws li to taub dab tsi yog cov qauv ntawm cov qhov database, yog tsim nyog ib tug los ze zog saib no phenomenon.

Feem ntau cov feem ntau, thaum koj tsim tau ib lub database yuav tsum ua raws li cov nram qab no yuav tsum tau. Nws yuav tsum yooj yim rau cov kev kho mob thiab yuav compact, devoid ntawm redundant ntaub ntawv. Nyob rau hauv ib qhov system hierarchical hais cov txheej txheem xws li hais tias bonds yog tsim nruab nrab ntawm lawv - tus me nyuam thiab leej niam leej txiv. Uas yog, cov ntaub ntawv no yog nyob saum toj no los yog hauv qab no nrog rau ib tug tej yam khoom system. Tab sis ib tug ntawm lawv yog ib txwm lub ntsiab, uas los ntawm tag nrho cov system pib. Raws li ib tug tshwm sim ntawm no arrangement ntawm cov ntaub ntawv blocks generated tsob ntoo database qauv uas yog cov yam ntxwv rau cov ntaub ntawv uas muaj feem xyuam rau computers.

Databases, faib nyob rau hauv lub network muaj tib lub yam ntxwv raws li cov xaab siab database. Qhov txawv nruab nrab ntawm lawv cov lus dag nyob rau hauv lub fact tias thawj tus me nyuam ntsiab yuav muaj ntau yam pog koob yawg koob.

Tab sis ua ntej koj xaiv nyob rau hauv kom meej cov qauv thiab cov hom, koj yuav tsum txhais tau lub tswvyim ntawm ib tug database. Yuav ua li cas yog meant by no lub sij hawm? Qhov yooj yim txhais yog li no: lub database - ib txoj kev rau Teacher thiab khw ntaub ntawv. Hom thiab cov hau kev ntawm Workers ntaub ntawv muaj heev heev. Txhua yam ntawm lawv muaj nws lub hom phiaj orientation, raws li tej yam uas yuav tsum tau. Piv txwv li, cov ntaub ntawv nyob rau hauv lub XML lus cob qhia raws li ib tsob ntoo, uas muaj branched paus thiab ntshav. Tab sis qhov no yog tsuas yog ib hom ntawm cov ntaub ntawv cia.

Cov xaab qauv ntawm database optimized rau kev nyeem ntawv, ceev cov ntaub ntawv xaiv thiab muab lawv rau cov neeg siv. Tab sis nws kuj muaj nws cov drawbacks. Piv txwv li, ib tug computer, ib qho yooj yim txaus rau kev khiav hauj lwm muaj ib lub cov ntaub ntawv los yog ntawv tais ceev tseg (uas yog yam hais txog qhov hierarchical qauv), ntev koom nyob rau hauv kev kuaj lub system rau cov kab mob. Qhov no qhia tau hais tias xws li ib tug system yog tsis haum rau cov ceev ceev sorting ntawm cov ntaub ntawv thiab, yog tias tsim nyog, cov txheej txheem yuav siv sij hawm ib tug ntev lub sij hawm. Cim ntawm lub ntsiab nyob rau hauv xws li ib tug qauv yog hais tias lub qis cov kwv yog, qhov ntau dua nws ua zes. Cuam tshuam rau hierarchical kev sib raug zoo ntawm leej niam leej txiv thiab tus me nyuam ntsiab ntawm lub cev.

Noteworthy yog lwm kev faib databases. Nws yuav tsum tau qhia nyob rau hauv kev txiav txim rau thaum kawg hais txog qhov teeb meem ntawm uas twb muaj lawm txoj kev ntawm cov ntaub ntawv cia. Los ntawm qhov xwm ntawm mov database ntaub ntawv muab faib ua cob (cov ntaub ntawv raws li cov cim), semi-structured (ntawv nyeem cov ntaub ntawv) thiab unstructured (semantic web). Structured databases muaj ob peb theem ntawm cov ntaub ntawv uas lwm cov nyob. Cov no muaj xws network thiab hierarchical database, qhov twg lub sib txuas lus yog teem ntawm tus neeg cov ntaub ntawv. Yog hais tias lub xaab siab database yog zoo li tsob ntoo, lub network tsa ib tug network. Nyob rau tib lub database qauv yog tsim los kom nws yuav nqa nyob rau hauv tej kab los sib ntsib thiab ntawm ib tug khub ntawm vertices tej zaum yuav ib tug ob peb mus. Piv txwv li, ib tug ntaub ntawv koom tes rau kev sib raug zoo nrog ntau, nrog rau cov tshwm sim hais tias nws cov hom yog tsis tsau. Nws yuav ua tau ib tug tswv cuab ntawm ib pawg ntawm cov ntaub ntawv (nruab nrab ntawm uas cov kev twb kev txuas yog hais tias) los yog tus tswv.

Muaj yog ib tug paub cov qauv database nyob rau hauv uas lub sib txuas lus ntawm cov ntaub ntawv txhais tau hais tias dynamically thaum lub sij hawm thaum ib tug thov txim. Databases yog txwv kom muab zais raws li lub hom ntawm cov ntaub ntawv muaj nyob rau hauv lawv, mus rau lub tseeb, documentary thiab lexicographical.

Yog li, lub database - ib tug qhia tshwj xeeb uas structured system, ib txoj kev khaws cia cov ntaub ntawv uas yuav ua tau tabular daim ntawv. Lub teeb ntawm ntau yam ntxhuav muaj ib zajlus kom kev twb kev txuas ntawm, thiab tsim tau lub database.